Pulling wall to wall isn't fast enough?

[Kolaina]

Most of the boss have very short cut scene, like 10-15 sec

if people couldn't even wait for that short period of time, I can see soon they will complain anyone who don't pop sprint whenever it is available

If this were the case, what’s so bad about missing 10 to 15 seconds of a fight? Might miss a raid wide, maybe a single aoe marker. Unlikely to even see a tank buster by this point.
Unless, they are longer than that and you are just down playing the length of cutscenes to add further scrutiny towards people who don’t wait? The latter sounds more likely